diff --git a/bin/gstack-artifacts-init b/bin/gstack-artifacts-init
index 8f97c3305..c182077fe 100755
--- a/bin/gstack-artifacts-init
+++ b/bin/gstack-artifacts-init
@@ -232,6 +232,11 @@ retros/*.md
 developer-profile.json
 builder-journey.md
 builder-profile.jsonl
+# Transcripts staged in remote-http MCP mode (per plan D11 split-engine).
+# gstack-memory-ingest persists per-run dirs here when local gbrain import
+# is skipped; brain admin pulls + indexes into the remote brain.
+transcripts/run-*/*.md
+transcripts/run-*/**/*.md
 # NOT synced (machine-local UX state):
 #   projects/*/question-preferences.json (per-machine UX preferences)
 #   projects/*/question-log.jsonl (audit/derivation log stays with preferences)
@@ -251,7 +256,9 @@ cat > "$GSTACK_HOME/.brain-privacy-map.json" <<'EOF'
   {"pattern": "builder-journey.md", "class": "artifact"},
   {"pattern": "projects/*/timeline.jsonl", "class": "behavioral"},
   {"pattern": "developer-profile.json", "class": "behavioral"},
-  {"pattern": "builder-profile.jsonl", "class": "behavioral"}
+  {"pattern": "builder-profile.jsonl", "class": "behavioral"},
+  {"pattern": "transcripts/run-*/*.md", "class": "behavioral"},
+  {"pattern": "transcripts/run-*/**/*.md", "class": "behavioral"}
 ]
 EOF
 
diff --git a/gstack-upgrade/migrations/v1.34.0.0.sh b/gstack-upgrade/migrations/v1.34.0.0.sh
new file mode 100755
index 000000000..ec196ac00
--- /dev/null
+++ b/gstack-upgrade/migrations/v1.34.0.0.sh
@@ -0,0 +1,92 @@
+#!/usr/bin/env bash
+# Migration: v1.34.0.0 — split-engine gbrain (remote MCP brain + optional
+#   local PGLite for code search per worktree).
+#
+# Per plan D5: prints a ONE-TIME discoverability notice for existing
+# Path 4 users who don't yet have a local engine. They learn that
+# symbol-aware code search (gbrain code-def / code-refs / code-callers)
+# is now available via /setup-gbrain Step 4.5 if they want it.
+#
+# When to print the notice (state match — all conditions must hold):
+#   - ~/.claude.json declares mcpServers.gbrain.{type|transport} = http|sse|url
+#     OR mcpServers.gbrain.url is set (remote-http MCP active)
+#   - ~/.gbrain/config.json is absent (no local engine yet)
+#   - User has not previously opted out via:
+#       ~/.claude/skills/gstack/bin/gstack-config set local_code_index_offered true
+#
+# When silent: anything else (Path 1/2/3 users, anyone already on PGLite,
+# anyone who opted out, anyone without remote-http MCP).
+#
+# Idempotency: writes a touchfile at ~/.gstack/.migrations/v1.34.0.0.done
+# on completion. Re-running this script is silent if the touchfile exists,
+# OR if local_code_index_offered=true.
+
+set -euo pipefail
+
+if [ -z "${HOME:-}" ]; then
+  echo "  [v1.34.0.0] HOME is unset — skipping migration." >&2
+  exit 0
+fi
+
+GSTACK_HOME="${GSTACK_HOME:-$HOME/.gstack}"
+MIGRATIONS_DIR="$GSTACK_HOME/.migrations"
+DONE_TOUCH="$MIGRATIONS_DIR/v1.34.0.0.done"
+CONFIG_BIN="$HOME/.claude/skills/gstack/bin/gstack-config"
+CLAUDE_JSON="$HOME/.claude.json"
+GBRAIN_CONFIG="$HOME/.gbrain/config.json"
+
+mkdir -p "$MIGRATIONS_DIR"
+
+# Idempotency: already-ran skips silently.
+if [ -f "$DONE_TOUCH" ]; then
+  exit 0
+fi
+
+# User opt-out skips silently AND records done.
+if [ -x "$CONFIG_BIN" ]; then
+  if [ "$("$CONFIG_BIN" get local_code_index_offered 2>/dev/null)" = "true" ]; then
+    touch "$DONE_TOUCH"
+    exit 0
+  fi
+fi
+
+# State match: remote-http MCP active?
+is_remote_http_mcp() {
+  [ -f "$CLAUDE_JSON" ] || return 1
+  command -v jq >/dev/null 2>&1 || return 1
+  local mtype murl
+  mtype=$(jq -r '.mcpServers.gbrain.type // .mcpServers.gbrain.transport // empty' "$CLAUDE_JSON" 2>/dev/null)
+  murl=$(jq -r '.mcpServers.gbrain.url // empty' "$CLAUDE_JSON" 2>/dev/null)
+  case "$mtype" in
+    url|http|sse) return 0 ;;
+  esac
+  [ -n "$murl" ] && return 0
+  return 1
+}
+
+# State match: local engine absent?
+is_local_engine_missing() {
+  [ ! -f "$GBRAIN_CONFIG" ]
+}
+
+if is_remote_http_mcp && is_local_engine_missing; then
+  cat <<'NOTICE'
+
+  ┌──────────────────────────────────────────────────────────────────┐
+  │  gstack v1.34.0.0 — split-engine gbrain                          │
+  │                                                                  │
+  │  Symbol-aware code search is now available on this machine.      │
+  │  Your remote brain at gbrain MCP keeps working as today; you can │
+  │  add a tiny local PGLite (~30s, no accounts) for `gbrain         │
+  │  code-def` / `code-refs` / `code-callers` queries per worktree.  │
+  │                                                                  │
+  │  Run /setup-gbrain to opt in at Step 4.5. Or skip this notice    │
+  │  permanently:                                                    │
+  │    gstack-config set local_code_index_offered true               │
+  └──────────────────────────────────────────────────────────────────┘
+
+NOTICE
+fi
+
+# Always touch done so we don't print again, regardless of state-match outcome.
+touch "$DONE_TOUCH"
diff --git a/test/gstack-upgrade-migration-v1_34_0_0.test.ts b/test/gstack-upgrade-migration-v1_34_0_0.test.ts
new file mode 100644
index 000000000..b22d8e1de
--- /dev/null
+++ b/test/gstack-upgrade-migration-v1_34_0_0.test.ts
@@ -0,0 +1,194 @@
+/**
+ * Unit tests for gstack-upgrade/migrations/v1.34.0.0.sh — split-engine notice.
+ *
+ * Per plan D5: print a one-time discoverability notice for existing Path 4
+ * (remote-http MCP) users who don't yet have a local engine, so they
+ * find /setup-gbrain Step 4.5. Silent for everyone else. Idempotent.
+ *
+ * Test matrix (5 cases):
+ *   1. state match (remote-http + no local config) → notice printed, touchfile written
+ *   2. state no-match (no MCP)                     → silent, touchfile written
+ *   3. state no-match (local config present)       → silent, touchfile written
+ *   4. opt-out via local_code_index_offered=true   → silent, touchfile written
+ *   5. idempotency: re-run after match is silent  → notice NOT re-printed
+ */
+
+import { describe, it, expect } from "bun:test";
+import {
+  mkdtempSync,
+  mkdirSync,
+  writeFileSync,
+  existsSync,
+  rmSync,
+  chmodSync,
+} from "fs";
+import { tmpdir } from "os";
+import { join } from "path";
+import { execFileSync, spawnSync } from "child_process";
+
+const MIGRATION = join(
+  import.meta.dir,
+  "..",
+  "gstack-upgrade",
+  "migrations",
+  "v1.34.0.0.sh",
+);
+
+interface MigEnv {
+  tmp: string;
+  home: string;
+  gstackHome: string;
+  doneTouch: string;
+  claudeJson: string;
+  gbrainConfig: string;
+  configBin: string;
+  cleanup: () => void;
+}
+
+function makeEnv(opts: {
+  remoteHttpMcp?: boolean;
+  hasLocalConfig?: boolean;
+  optedOut?: boolean;
+}): MigEnv {
+  const tmp = mkdtempSync(join(tmpdir(), "migration-v1340-"));
+  const home = join(tmp, "home");
+  const gstackHome = join(home, ".gstack");
+  const gbrainDir = join(home, ".gbrain");
+  const claudeSkillsBin = join(home, ".claude", "skills", "gstack", "bin");
+  const claudeJson = join(home, ".claude.json");
+  const gbrainConfig = join(gbrainDir, "config.json");
+  const configBin = join(claudeSkillsBin, "gstack-config");
+
+  mkdirSync(home, { recursive: true });
+  mkdirSync(gstackHome, { recursive: true });
+  mkdirSync(gbrainDir, { recursive: true });
+  mkdirSync(claudeSkillsBin, { recursive: true });
+
+  if (opts.remoteHttpMcp) {
+    writeFileSync(
+      claudeJson,
+      JSON.stringify({
+        mcpServers: {
+          gbrain: { type: "http", url: "https://wintermute.example/mcp" },
+        },
+      }),
+    );
+  } else {
+    writeFileSync(claudeJson, JSON.stringify({ mcpServers: {} }));
+  }
+
+  if (opts.hasLocalConfig) {
+    writeFileSync(gbrainConfig, JSON.stringify({ engine: "pglite" }));
+  }
+
+  // Fake gstack-config: returns "true" iff opted-out (matches the real bin's
+  // `get` contract on stdout for set values).
+  const optedOutResponse = opts.optedOut ? "true" : "false";
+  writeFileSync(
+    configBin,
+    `#!/bin/sh
+if [ "$1" = "get" ] && [ "$2" = "local_code_index_offered" ]; then
+  echo "${optedOutResponse}"
+  exit 0
+fi
+exit 0
+`,
+  );
+  chmodSync(configBin, 0o755);
+
+  return {
+    tmp,
+    home,
+    gstackHome,
+    doneTouch: join(gstackHome, ".migrations", "v1.34.0.0.done"),
+    claudeJson,
+    gbrainConfig,
+    configBin,
+    cleanup: () => rmSync(tmp, { recursive: true, force: true }),
+  };
+}
+
+function runMigration(env: MigEnv): { stdout: string; stderr: string; exitCode: number } {
+  const result = spawnSync("bash", [MIGRATION], {
+    encoding: "utf-8",
+    timeout: 5_000,
+    env: {
+      ...process.env,
+      HOME: env.home,
+      GSTACK_HOME: env.gstackHome,
+      // The script looks for gstack-config at $HOME/.claude/skills/gstack/bin
+      // which is already in env.home; nothing else needed.
+    },
+  });
+  return {
+    stdout: result.stdout || "",
+    stderr: result.stderr || "",
+    exitCode: result.status ?? 1,
+  };
+}
+
+describe("gstack-upgrade/migrations/v1.34.0.0.sh", () => {
+  it("STATE MATCH: remote-http MCP + no local config → notice printed, touchfile written", () => {
+    const env = makeEnv({ remoteHttpMcp: true, hasLocalConfig: false });
+    try {
+      const r = runMigration(env);
+      expect(r.exitCode).toBe(0);
+      expect(r.stdout + r.stderr).toContain("split-engine");
+      expect(r.stdout + r.stderr).toContain("/setup-gbrain");
+      expect(existsSync(env.doneTouch)).toBe(true);
+    } finally {
+      env.cleanup();
+    }
+  });
+
+  it("NO MATCH: no MCP at all → silent, touchfile written", () => {
+    const env = makeEnv({ remoteHttpMcp: false, hasLocalConfig: false });
+    try {
+      const r = runMigration(env);
+      expect(r.exitCode).toBe(0);
+      expect(r.stdout + r.stderr).not.toContain("split-engine");
+      expect(existsSync(env.doneTouch)).toBe(true);
+    } finally {
+      env.cleanup();
+    }
+  });
+
+  it("NO MATCH: local config present → silent, touchfile written", () => {
+    const env = makeEnv({ remoteHttpMcp: true, hasLocalConfig: true });
+    try {
+      const r = runMigration(env);
+      expect(r.exitCode).toBe(0);
+      expect(r.stdout + r.stderr).not.toContain("split-engine");
+      expect(existsSync(env.doneTouch)).toBe(true);
+    } finally {
+      env.cleanup();
+    }
+  });
+
+  it("OPT-OUT: local_code_index_offered=true → silent, touchfile written", () => {
+    const env = makeEnv({ remoteHttpMcp: true, hasLocalConfig: false, optedOut: true });
+    try {
+      const r = runMigration(env);
+      expect(r.exitCode).toBe(0);
+      expect(r.stdout + r.stderr).not.toContain("split-engine");
+      expect(existsSync(env.doneTouch)).toBe(true);
+    } finally {
+      env.cleanup();
+    }
+  });
+
+  it("IDEMPOTENT: second run after match is silent (touchfile already present)", () => {
+    const env = makeEnv({ remoteHttpMcp: true, hasLocalConfig: false });
+    try {
+      const first = runMigration(env);
+      expect(first.exitCode).toBe(0);
+      expect(first.stdout + first.stderr).toContain("split-engine");
+
+      const second = runMigration(env);
+      expect(second.exitCode).toBe(0);
+      expect(second.stdout + second.stderr).not.toContain("split-engine");
+    } finally {
+      env.cleanup();
+    }
+  });
+});